Oscillation device and communication system

Abstract

An oscillation device includes a voltage control oscillation unit, a dividing unit, an output phase comparison unit, and a control voltage supply unit. The voltage control oscillation unit is configured to oscillate an oscillation frequency signal with a frequency f1 according to a control voltage. The dividing unit is configured to divide the frequency of the oscillation frequency signal into 1/N (N is a natural number) to match with a frequency f2 of a reference frequency signal input from outside. The output phase comparison unit is configured to compare a phase of the divided oscillation frequency signal with a phase of the reference frequency signal and output a signal according to a phase difference. The control voltage supply unit is configured to generate a control voltage according to the signal according to the phase difference and supply the control voltage to the voltage control oscillation unit.

What is claimed is: 
     
         1 . An oscillation device, comprising:
 a voltage control oscillation unit, configured to oscillate an oscillation frequency signal with a frequency f1 according to a control voltage;   a dividing unit, configured to divide the frequency of the oscillation frequency signal into 1/N to match with a frequency f2 of a reference frequency signal input from outside, wherein N is a natural number;   a phase comparison unit, configured to compare a phase of the divided oscillation frequency signal with a phase of the reference frequency signal and output a signal according to a phase difference; and   a control voltage supply unit, configured to generate a control voltage according to the signal according to the phase difference and supply the control voltage to the voltage control oscillation unit, wherein   the oscillation device is configured to output the divided oscillation frequency signal to outside.   
     
     
         2 . The oscillation device according to  claim 1 , wherein
 N of the dividing unit is a natural number equal to or more than two.   
     
     
         3 . The oscillation device according to  claim 1 , wherein
 N of the dividing unit is one.   
     
     
         4 . The oscillation device according to  claim 1 , wherein
 the voltage control oscillation unit is an oven controlled crystal oscillator.   
     
     
         5 . The oscillation device according to  claim 1 , wherein
 when an input of the reference frequency signal is interrupted, the oscillation device is configured to fix a control voltage supplied to the voltage control oscillation unit at a control voltage when the reference frequency signal is interrupted and continue the output of the oscillation frequency signal to outside.   
     
     
         6 . A communication system, comprising:
 the oscillation device according to  claim 1 ; and   a device, configured to use the divided oscillation frequency signal output from the oscillation device as an external synchronization signal.